Nature Without Biodiversity: Urban Climate Adaptation Has a Blind Spot

Many conservationists see urban climate adaptation as a win-win endeavor. After all, making cities more resilient to weather extremes often involves using nature: wetlands to absorb heavy rainfall, trees to lower local temperatures, and so on. Billions of dollars are being spent, and all this new nature ought to be a boon to biodiversity—yet the potential is in danger of being squandered.

In a study published in the journal Geo: Geography and Environment, researchers led by Natalie Butt, an ecologist at the University of Queensland, reviewed climate adaptation plans from 80 cities around the world. Greenery is ubiquitous in them, but “just 18 percent of the plans assessed contained specific intentions to promote biodiversity,” they found.

And what an opportunity it is. The researchers extracted spatial data from 58 of those plans; they covered some 5,872 kilometers of waterways, along with 12,917 square kilometers of proposed reforestation. That’s “an area one and a half times the size of Yellowstone National Park,” wrote Butt and colleagues. Extrapolated to urban areas worldwide, “it would amount to re-forestation of approximately 1.4 million km², or nearly half the total area of national parks in the world.”

Even the non-extrapolated figure still overlaps with the range of 271 threatened animal species, estimate the researchers, and the waterways with 91 threatened freshwater species. Cities might prove vital to their conservation. And there are other lenses than rarity through which to view urban biodiversity: cities are also home to a great many non-threatened creatures, and are a potentially important link in larger ecological communities.

All that, however, went largely unmentioned in the resilience plans analyzed by Butt’s team. Though they would still have biodiversity benefits—regardless of whether people have animals in mind, vegetation is better than pavement — far more would be possible if these new landscapes were designed and managed with nonhuman communities in mind.

There’s also a danger that, as urban nature is engineered without much thought of biodiversity, the very concept of nature could be subtly redefined for city-dwellers. “Due to our unavoidably anthropogenic perspective on most things,” says Butt, “we usually only see things in terms of how they relate to us.” Rather than containing rich communities of life, nature might become a utilitarian aesthetic.

It doesn’t need to be that way. The researchers called attention to Amsterdam as a city that’s explicitly enlarging protected areas to enhance extreme-weather resilience and allow for animal migration. Butt mentioned London’s Walthamstow Wetlands, a nature reserve opened in 2017 with both people and migratory birds in mind. Examples exist for joining climate adaptation and biodiversity. More people just need to follow them.